ENCODERS AND DECODERS EMPLOYING LOG-POLAR COORDINATE SYSTEM

An encoder for encoding images includes at least one processor configured transform a given input pixel of an input image having (x, y) coordinates in a Cartesian coordinate system into a given transformed pixel of a transformed image having (ρ, θ) coordinates in a log-polar coordinate system, using a log-polar transformation in which a radial distance (φ of the given transformed pixel is a logarithm of a distance of the given input pixel from an origin in the Cartesian coordinate system, and an angular distance (θ) of the given transformed pixel is a sum of an arctangent of a slope of a line connecting the given input pixel to the origin and a function of the radial distance, encode the transformed image, by employing a compression algorithm, into an encoded image, and send the encoded image to a display apparatus for subsequent decoding thereat.